1. Field of the Invention
The present invention generally relates to computer and wireless self-organizing networks. More particularly, the invention relates to protocols for forming and operations of a network within a plurality of interconnected wireless devices utilizing the geographic location information of the wireless devices. Even more specifically, the present invention is for self-organizing networks that are comprised of pervasive, simple, and low power wireless devices.
2. Description of the Related Art
In computers, a network allows the transfer of data, typically in discrete segments called xe2x80x9cpacketsxe2x80x9d or xe2x80x9cframes,xe2x80x9d within a plurality of computers. Networks are readily scalable, from a small local area network (LAN), such as an Ethernet, to the largest network, the Internet. Furthermore, a network can be created through cabling that physically interconnects the computers, and the data packets are transferred in electrical or optical signals across the cabling. Alternately, a partial or full wireless network can be created through devices communicating through extant wireless media.
The general term xe2x80x9cwireless networkingxe2x80x9d refers to technology that enables two or more computers to communicate using standard network protocols, but without network cabling. Strictly speaking, any technology that does this could be called wireless networking. The most common wireless network is a wireless LAN. Wireless LAN technology has been fuelled by the emergence of cross-vendor industry standards such as IEEE 802.11, and has produced a number of affordable wireless solutions that are growing in popularity with business and schools as well as sophisticated applications where network wiring is impossible, such as in warehousing or point-of-sale handheld equipment.
There are commonly two kinds of wireless networks: ad-hoc or access-point (a xe2x80x9chubxe2x80x9d). An ad-hoc, or peer-to-peer wireless network consists of a number of computers each equipped with a wireless networking interface card. Each computer can communicate directly with all of the other wireless enabled computers and share files and peripheral devices in this way, but may not be able to access wired LAN resources unless one of the computers acts as a bridge to the wired LAN using special software. (This is called xe2x80x9cbridgingxe2x80x9d).
An access point, or base station or other dedicated device, can be used to construct a wireless network wherein the access point acts like a hub to provide connectivity for the wireless computers. The access point can connect, or bridge, the wireless LAN to a wired LAN, allowing wireless computer access to LAN resources, such as file servers or existing Internet connectivity. There are two common types of access points: dedicated hardware access points (HAP) such as Lucent""s WaveLAN, Apple""s Airport Base Station or WebGear""s AviatorPRO; or software access points which run on a computer equipped with a wireless network interface card as used in an ad-hoc or peer-to-peer wireless network. Routers can be used as a basic software access point, and include features not commonly found in hardware solutions, such as Direct PPPoE support and extensive configuration flexibility.
Wireless networking hardware requires the use of underlying technology that deals with radio frequencies, or light wave manipulation, as well as data transmission. The most widely used standard, IEEE 802.11, defines the salient aspects of radio frequency wireless networking. Because most wireless networking hardware vendors support the 802.11 standard, the networks can interoperate with the common data transmission standard.
Further, a wireless and wired network can intercommunicate with an appropriate bridge therebetween. A bridge can be accomplished either with a hardware access point or a software access point where the data can pass through the access point in between the networks. Hardware access points are available with various types of network interfaces, such as Ethernet or Token-Ring, but typically require extra hardware to be purchased. And a software access point does not limit the type or number of network interfaces and also allows considerable flexibility in providing access to different network types, such as different types of Ethernet, Wireless and Token-Ring networks.
In a wireless network, a wireless computer, such as a cell phone, pager, or personnel digital assistant (PDA), can xe2x80x9croamxe2x80x9d from one access point to another, with the software and hardware maintaining a steady network connection, typically by monitoring the signal strength from in-range access points and locking on to the one with the best quality. The maintenance of the connection while the wireless device roams is completely transparent to the user. In such configuration, access points are required to have overlapping wireless areas to achieve geographical area coverage. A problem arises in that the several wireless devices of the network can roam within the network and change the path along which the data packets must travel in order to reach the device.
It is well known how to locate the shortest path for data to travel between nodes in a fixed network. Exemplary algorithms such as the Bellman-Ford and Dijkstra algorithms find the shortest paths from a single source vertex (or node) to all other vertices (or nodes) in a weighted, directed graph, such as in a network topology. The algorithms initialize the distance to the source vertex to 0 and all other vertices to ∞. It then does V-1 passes (V is the number of vertices) over all edges relaxing, or updating, the distance to the destination of each edge. Finally, each edge is checked again to detect negative weight cycles in which case it returns false. The time complexity for most shortest path algorithms is O(n2), which is a significant allocation of computer resources. This problem becomes exacerbated in a wireless network where the devices (nodes) are constantly moving, and thus, the shortest path must be continually updated in order to have an optimal network between the wireless devices.
Accordingly, it would be advantageous to provide a system and method for providing a network protocol whereby a plurality of wireless devices self-organize themselves, and can create an optimal wireless network between the wireless devices without constantly utilizing a shortest path algorithm with the algorithm""s associated overhead. Such system and method should utilize the resources of the wireless devices as intelligent nodes within the network to assist in determining the shortest paths of the optimal network. It is thus to such a system and method for creating a network within geographically randomly located wireless devices that the present invention is primarily directed.